commit 1020c797324e6f8707157f8bca2a6d7f68429b3c Author: George Kadianakis desnacked@riseup.net Date: Tue May 10 11:10:12 2016 -0400

prop224: Bump keylen to 2 bytes in all cells. --- proposals/224-rend-spec-ng.txt | 21 ++++++--------------- 1 file changed, 6 insertions(+), 15 deletions(-)

diff --git a/proposals/224-rend-spec-ng.txt b/proposals/224-rend-spec-ng.txt index 408a982..365f4fd 100644 --- a/proposals/224-rend-spec-ng.txt +++ b/proposals/224-rend-spec-ng.txt @@ -1067,7 +1067,7 @@ Table of contents: sends an ESTABLISH_INTRO cell with the following contents:

AUTH_KEY_TYPE [1 byte] - AUTH_KEY_LEN [1 byte] + AUTH_KEY_LEN [2 bytes] AUTH_KEY [AUTH_KEY_LEN bytes] N_EXTENSIONS [1 byte] N_EXTENSIONS times: @@ -1075,8 +1075,8 @@ Table of contents: EXT_FIELD_LEN [1 byte] EXT_FIELD [EXT_FIELD_LEN bytes] HANDSHAKE_AUTH [MAC_LEN bytes] - SIGLEN [1 byte] - SIG [SIGLEN bytes] + SIG_LEN [2 bytes] + SIG [SIG_LEN bytes]

The AUTH_KEY_TYPE field indicates the type of the introduction point authentication key and the type of the MAC to use in @@ -1100,7 +1100,7 @@ Table of contents: section 5.2, "Setting circuit keys". It prevents replays of ESTABLISH_INTRO cells.

- SIGLEN is the length of the signature. + SIG_LEN is the length of the signature.

SIG is a signature, using AUTH_KEY, of all contents of the cell, up to but not including SIG. These contents are prefixed with the string @@ -1123,15 +1123,6 @@ Table of contents: Otherwise, the node must associate the key with the circuit, for use later in INTRODUCE1 cells.

- [TODO: The above will work fine with what we do today, but it will do - quite badly if we ever freak out and want to go back to RSA2048 or - bigger. Do we care?] - [Do we lose much by making AUTH_KEY_LEN and SIGLEN 2 bytes each? Or, - even crazier, do we lose much by making those two variable sizes, - defined by whichever value of AUTH_KEY_TYPE you pick? I guess we - don't know how big it is if we don't recognize the key type, but we - are already planning to refuse the intro request then. -RD] - 3.1.2. Registering an introduction point on a legacy Tor node [LEGACY_EST_INTRO]

Tor nodes should also support an older version of the ESTABLISH_INTRO @@ -1203,7 +1194,7 @@ Table of contents:

LEGACY_KEY_ID [20 bytes] AUTH_KEY_TYPE [1 byte] - AUTH_KEY_LEN [1 byte] + AUTH_KEY_LEN [2 bytes] AUTH_KEY [AUTH_KEY_LEN bytes] N_EXTENSIONS [1 byte] N_EXTENSIONS times: @@ -1294,7 +1285,7 @@ Table of contents: EXT_FIELD_LEN [1 byte] EXT_FIELD [EXT_FIELD_LEN bytes] ONION_KEY_TYPE [1 bytes] - ONION_KEY_LEN [1 bytes] + ONION_KEY_LEN [2 bytes] ONION_KEY [ONION_KEY_LEN bytes] NSPEC (Number of link specifiers) [1 byte] NSPEC times: